Process of treating hides and skins



amines such as, for

Patented Mar.'2 2, 1938,

UNITED STATE PROCESS OF TREATING HIDES AND SKINS Christoph Thomson, Ernst Koch,

many, tiengesellschaft,

, \manymw Frankfort-on-the-Main, assignors to I. G.

Frankfort-on-the-Main,

Alfred Eckelmann, and

Ger- Farbenindustrie Ak- Ge No Drawing. Application December 17, 1935 Serial No. 54,944. 1934 4 Claims.

The present invention relates to a, process of treating hides and skins.

We have foundtha't hides and skins are improved by a treatment with basic compounds, 5 containing nitrogen and having a straight or. branched, saturated or unsaturated carbon chain of at least 5 carbon atoms, or a hydroaromatic ring containing at least 5 members, in the form of their addition salts. The carbon chain may be interrupted by other atoms or atom groups such-as, for instance, by O, S, N, CO, CONH, but at least 5 carbon atoms must directly be connected with each other. The substitution products and derivatives of these bodies may also be used.

As such compounds be named: amines, aminooxides, imidazoles, imidazolines, pyrimidines; furthermore imidoethers, imidothioethe'rs andamidines, the last three obtainable, for instance, according to the co-pending U. S. application Serial No. 751,252 and 751,253, filed November 2, 19 34, in the name of Alfred Eckelmann and Ernst Koch, furthermoresubstituted ureas, thioureas, guanidines and carbaminic acid esters.

There may be used, for instance, the addition salts of the following bodies: octylamine, dodecylamine, stearylamine, the technical fatty instance, mixtures of amines prepared from coco-nut oil fatty acid, palm nut oil fatty acid or from technical stearic acid, the amines made from technical montanic acidor naphthenic acid, abietylamine, paraoctylaniline,

monom'ethylstearylamine, octylglucamine, monooleylhydroxy-propylenediamine, stearoyldiethylenediamine, decylhexahydrophenylamine, .N- octylaniline, N-stearyl-para-phenylenediamine, N-dodecylnaphthylamine, dodecylfurfurylamine,

40 dimethyldodecylamine, dodecylmethylglucamine,

asymmetric ethyloctylethylenediamine, N-dioctylaniline, dimethyldodecylamineoxide; furthermore N-methylstearbenzimidazole, 'N-dodecylacetbenzimidazole, N-stearoylhydroxyethylacetbenzimidazole, laurimida-zoline, I- T-d0decylpyrimidine, stearimidomethylether, laurimidobutylether,- the imidoisobutylether of coco-nut oil fatty acid, benzimidodecylether, acetirnidostearylether, stearimidomethylthioether, stearamidine, the amidine of palm nut oil fatty acid,

symmetrical and asymmetrical steardiethylamidine, steardiethylamino-ethylamidine, stearoxethylamidine, monoestearylurea, asymmetrical dodecylaminoethylurea, asymmetrical decylmethylolurea, N-stearyl-N'-diethylaminoethyl-' there may, for instance, primary, secondary and tertiary In Germany December 22,

chloride, of stearic acid diethylamide with stear-- amidine hydrochloride. Insofar as these bodies are be used withoutapplication of solvents, otherwise they may suitably be used in the form of an aqueoussolution, or in case they are not sufficiently soluble in water in the form of an emulsion. If necessary, conjunction with organic solvents, oils and the like or with dispersing agents.

The said products are well absorbed by hide and skin. They may be applied before or during the tanning process. The leathers and furs which have been prepared from hides and skins acid liquid, they may they may be applied in either pre-treated with the said products or in the presence of the said products, show an agreeable soft feel. The tanning process takes place more uniformly and more rapidly. The products, furthermore, prevent in many cases deleterious influences on the fiber, and, 'with the aid of these products there may be obtained leathers of very good resistance to tearing. Since 'many of these products are fast to light, they may be used with great advantage for the manufacture of leathers fast to light, especially white leathers. The products-may also be used for treating such hides and skins which are not intended to be worked up immediately, for instance, by tanning. The products have a preserving action and prevent the fiber from being detrimentally affected;

proved in many cases that the skins or hides thus treated may again very easily be soaked, if necessary with addition of other soaking agents.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto; the parts are by weight:

(1) 50 parts of calf skin are drummed in an aqueous solution of .125 parts of water and 10 parts of the diethylamidine hydrochloride, prepared from commercial stearic acid until the skin has absorbed a suificient quantity of the product. 3 parts of a formaldehyde solution of furthermore it has I parts of benzoquinone.

30 per cent. strength are now added to the solution and the skin is subsequently drummed for hours. The leather is then washed and dried in the usual manner. The leather thus obtained is white and fast to light and possesses a high resistance to tearing.

(2) 100 parts 01' sheep skin are drummed for hours in a solution which contains per liter of liquor 100 parts of amidine hydrochloride, prepared from the nitrile of coco-nut oil fatty acid, and 25 parts of formaldehyde solution of 30 per cent, strength. The skin is well washed and dried in the usual manner. The leather obtained has the properties of that described in Example 1.

(3) 100 parts of pickled goat skin are well drummed for 5 hours in an aqueous solution of 150 parts of water and 3 parts of benzoquinone and treated in a fresh liquor containing the imidazoline hydrochloride prepared from commercial stearic acid. The leather may advantageously be after-treated in the usual manner.

(4) 80 parts of well de-limed sheep skin are treated in a solution which contains per liter of liquor 70 parts of imidomethylether hydrochloride prepared from technical stearic acid, 50 parts of the product of the reaction of oleic acid chloride on methyl-taurine and parts of a formaldchyde solution of 30 per cent. strength.

(5) 100 parts of calf skin are drummed for hours in an aqueous solution of 250 parts of water. 5 parts of lauramidine hydrochloride and 5 A brown soft leather is obtained which resists tearing.

(6) 80 parts of calf skin are first pre-treated with a solution of 8.5 parts of the diethylamidine hydrochloride prepared from commercial stearic acid and 3.5 parts of dodecylurea in 250 parts of water. Later on, 3 parts of acetaldehyde are added to this liquor and the skin is then afterdrummed for a short time. A soft, feebly yellow leather of very good resistance to tearing is obtained.

(7) 50 parts of prepared rabbit skin are treated with an aqueous solution consisting of 100 parts of water and 10 parts of unsymmetrical diethylamidine hydrochloride prepared from technical stearic acid, until the skin has absorbed enough of the product. The skin is then after treated with a formaldehyde solution of 3 per cent.

.strength. A soft fur is obtained which has a very good resistance to tearing.

(8) 100 parts of cow hide are shaken for 3 days with 300 parts of water, containing 10 parts of the diethylaminoethylamidine hydrochloride prepared from-commercial stearic acid; thereupon the hide is rinsed for a short time and:

tanned with a tanning agent prepared according to German Patent No. 436,446 from colophonium-cresol. The pre-treatment essentially enhances the fastness to tearing of the leather.

(9) 75 parts of calf skin are shaken for 3 days with a solution of 7.5 parts of stearoyldiethylethylenediamine hydrochloride in 200 parts of water. The leather is then rinsed and shaken with300 parts of a solution which contains 15 parts of ammoniacal iron alum. To this tannirg solution there are added in three equal portions and n in intervals of 3 hours '75 parts of a sodium acetate solution of 10 per cent. strength. The leather is then shaken for a further 2 days, thereupon rinsed and dried. The leather is very well and uniformly tanned, is not streaky in the cut, has a full and soft feel a good resistance to tearing and shows only a feeble tendency to grain-cracking.

We claim:

1. The process which comprises treating untanned hides and skins with the salts of basic compounds selected from the group consisting of compounds of the general formula:

and of the general formula:

and of the general formula:

. Nf-CH2 least 5 carbon atoms.

3. The process which comprises treating untanned hides and skins with asymmetric diethylamidine-hydrochloride, derived from commercial stearic acid.

4. Hides and skins,which have been improyed by treating the untanned materials with the salts of basic compounds selected from the group consistlng of compounds of the general formula:

wherein x stands for CR1 or SR1; R; R1, R: and

radicals having a cyclo-aliphati'c ring, at least pound containing at least 5 carbon atoms.

CHRISTOPH THOMSEN. ALFRED EC ERNST K QLH.

one of the substituent radicals in said basic com- 

